LOCATION TACAES AK

Established Series
SDB/MJS
08/2025

TACAES SERIES

Depth class: very deep
Drainage class: very poorly drained
Parent material: organic material over coarse-loamy glaciolacustrine deposits
Landscape: lake plains, till plains, outwash plains and mountains
Landform: depressions on lacustrine terraces, glacial valley floors, river valleys and lake plains
Slope: 0 to 4 percent
Mean annual precipitation: about 350 mm (14 in)
Mean annual air temperature: about -3 degrees C (27 degrees F)
Frost-free period: 20 to 103 days

TAXONOMIC CLASS: Loamy, mixed, euic Terric Cryohemists

TYPICAL PEDON: Tacaes peat in a water sedge community on a lacustrine terrace depression on a 0 percent slope at an elevation of 547m (1795 ft).

Oi--0 to 40 cm (0 to 16 in); peat, very dark gray (7.5YR 3/1) rubbed moist; nonsticky, nonplastic; common very fine, fine, and medium roots throughout; neutral (pH 6.9); gradual smooth boundary (10 to 50 cm, 4 to 20 in)

Oe--40 to 90 cm (16 to 35 in); mucky peat, very dark brown (7.5YR 2.5/2) rubbed moist; nonsticky, nonplastic; common very fine, fine and medium roots throughout; neutral (pH 6.6); abrupt smooth boundary (42 to 60 cm, 17 to 24 in)

Cg1--90 to 120 cm (35 to 47 in); silt loam, dark gray (N 4/), reduced moist; massive; slightly hard, friable, slightly sticky, nonplastic; nonsmeary; neutral (pH 6.8); gradual smooth boundary (10 to 46 cm, 4 to 18 in)

Cg2--120 to 180 cm (47 to 71 in); silt loam, 70 percent dark gray (N 4/), reduced and 30 percent dark gray (5Y 4/1) reduced moist; massive; slightly hard, friable, slightly sticky, nonplastic; nonsmeary; neutral (pH 7.1). (24 to 78 cm, 9 to 31 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 62.31715, longitude -145.50073, UTM 6910411.92 north and UTM 577704.94 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: cryic
Mean annual soil temperature: -1 to 5 degrees C. (30 to 41 degrees F)
Thickness of organic material: 52 to 110 cm (20 to 43 in)
Thickness of hemic soil material: 42 to 60 cm (17 to 24 in)
Thickness of fibric soil material: 10 to 50 cm (4 to 20 in)
Depth to redoximorphic depletions: 52 to 110 cm (20 to 43 in)
Aquic conditions: 0 to 180 cm (0 to 71 in)

Oi, Oe, Oa horizons:
Hue: 7.5YR or 10YR
Value: 2 to 4
Chroma: 1 to 3
Texture: peat, mucky peat, muck
Organic matter: 60 to 90 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.3)

Cg horizons:
Hue: 2.5Y, 5Y or N
Value: 4 to 7
Chroma: 0 to 2
Texture: Sandy loam, silt loam, loam, clay loam
Sand: 15 to 55 percent
Silt:14 to 80 percent
Clay: 5 to 32 percent
Rock fragments: 0 percent
Organic matter: 0 to 1.5 percent
Reaction class: slightly acid to neutral (pH 6.1 to 7.3)

Some pedons have an A horizon between the organic matter and parent material with a highly organic silt loam texture, hue of 10YR or 2.5Y, value of 2 to 3, and chroma of 1 to 2, and a slightly acidic to neutral pH.

COMPETING SERIES: These are the Aginaktuk, Doroshin, Hewitt, Mineralcreek, Runkelscreek, Stanbro, and Tepete soils.
Aginaktuk soils have a dark grey (10YR 4/1) matrix with mottles in the uppermost mineral horizon and lack a fibric horizon.
Doroshin soils lack sapric soil material and have a clay content range of less than 3 percent
Hewitt soils have mineral strata between organic horizons.
Mineralcreek soils have A horizons and occur on flood plains in till plains.
Runkelscreek soils have ponding and mineral substratum textures of loam and very fine sandy loam.
Stanbro soils have a mean annual air temperature of 4 degrees C (39 degrees F) and gravelly clay loam textures in the mineral horizons.
Tepete soils have 18 to 35 percent clay in the mineral substratum and have a mean annual air temperature of 1 to 6 degrees C (34 to 43 degrees F)

GEOGRAPHIC SETTING:
Elevation: 400 to 1000 meters (1310 to 3280 ft)
Parent material: organic material over coarse-loamy glaciolacustrine deposits
Landform: depressions on lacustrine terraces
Slopes: 0 to 4 percent
Mean annual precipitation: 300 to 500 mm (12 to 20 in)
Mean annual air temperature: -5 to -1 degrees C. (23 to 30 degrees F)
Frost-free period: 20 to 103 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chelina, Eskilida, Glennallen, Greylingcreek, Klasi, Klawasi, and Kluna, soils.
Chelina soils are well drained, have a cambic horizon, have clay loam textures in the parent material, and occur on lacustrine terraces.
Eskilida soils are poorly drained, have a folistic epipedon, and occur on terraces in river valleys.
Glennallen soils are poorly drained, have permafrost, have a histic epipedon, have cryoturbation, and occur on river valleys and lacustrine terraces in outwash plains and lake plains.
Klasi soils are mineral soils, have permafrost, have a histic epipedon, and occur on lacustrine terraces.
Klawasi soils have permafrost, have histic epipedons, have a loess cap over clayey lacustrine sediments, and occur on lacustrine terraces.
Kluna soils are well drained, have stratified horizons of sandy and silty alluvium, and occur on stream terraces and floodplains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: very poorly drained
Saturated Hydraulic Conductivity: High in the Oi, Oe, Cg2 and Cg2 horizons.
Permeability: moderately rapid in the Oi, Oe, Cg2 and Cg2 horizons.
Runoff: negligible

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: water sedge

DISTRIBUTION AND EXTENT: MLRA 227 Copper River Basin
Extent: moderate

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 90 to 120 cm (35 to 47 in)

Aquic conditions: 0 to 180 cm (0 to 71 in) (Oi, Oe, Cg1 and Cg2 horizons)

Hemic material: 40 to 90 cm (16 to 35 in) (Oe horizon)

Reduced matrix: 90 to 180 cm (35 to 71 in) (Cg1 and Cg2 horizons)

ADDITIONAL DATA:

User pedon Id: 2016AK261024

National Cooperative Soil Survey
U.S.A.